Kural - 622

Though sorrow, like a flood, comes rolling on,
When wise men's mind regards it,- it is gone

Explanation
A flood of troubles will be overcome by the (courageous) thought which the minds of the wise will entertain, even in sorrow.

Tamil Transliteration
Vellath Thanaiya Itumpai Arivutaiyaan
Ullaththin Ullak Ketum.